In recent years, the variety of antimicrobial agents has increased substantially, along with a parallel increase in resistant pathogenic microorganisms. Resistance is now recognized against all clinically available antimicrobial agents. The response to antimicrobial resistance in the medical community has been to use new or alternative antibiotics not previously used against the resistant bacteria. This approach has required the continuous development of new antibiotics, either as modifications of currently existing compounds or as combinations of compounds that may inhibit or bypass the bacterial resistance mechanisms.
It is an object of the present invention to provide new polypeptides having improved antimicrobial activity and polynucleotides encoding the polypeptides.
Another object of the invention is to provide new antimicrobial polypeptides which may have reduced hemolytic activity and/or reduced cytotoxicity. The polypeptides may also exhibit reduced sensitivity towards cations, such as Ca2+, Mg2+, and Na+.